Basic Concepts - mqtt/mqtt.org GitHub Wiki

A brief introduction to some of the concepts found in MQTT can be found in the MQTT manpage on the mosquitto website.

Another brief introduction can be found in the Eclipse Newsletter on the Eclipse website.

There is a very nice overview of MQTT available here: What is MQTT and how does it work with WebSphere MQ?

PubSub Messaging

Some useful information on topics can be found at Topic semantics and usage.